The German-based holding company Innolas and its four sister companies provide customers all over the world with laser technology for industrial and scientific applications. The Innolas Semiconductor division specializes in wafer marking and wafer sorting solutions for the semiconductor industry. For over 20 years, customer-specific solutions have been the core business of the company, which has 25 employees.

"Our customers are supplied with cleanroom-ready machines for their production facilities," says Thomas Rölz from Sales, describing a unique selling point of the Krailing-based company. Its references include numerous 'global players' in the wafer and chip industry. Around 20 to 30 special machines leave the company every year, around half of which go to Asia and the USA. Head of Development Sven Wollstadt adds: "We have our customers to thank for the fact that we have also been manufacturing wafer sorting systems since 2001. Originally, we only had laser markers in our range until a user approached us. He was of the opinion that we could also produce the sorters with our technology." Such a wafer sorting or wafer transfer machine is the 'IL C3800', which is now equipped with mechatronic grippers or swivel units for the first time.

They launched the solution together: Sven Wollstadt, Head of Development at Innolas Semiconductor (right), and Harry Kern, Technical Consultant at Gimatic.

© Gimatic

In a modular wafer processing system, there are transport systems between the individual stations that transport the wafers from one station to another. As absolute clean room conditions prevail here, this handling must be fully automated. Care must also be taken not to touch the front or back of the wafer with the robot in order to prevent contamination.

The IL C3800 has the task of automatically opening a cleanroom-compatible FOUP (front open unit pot) plastic box, removing the wafers it contains, turning them over, aligning them and transferring them to the downstream processing unit. A three-axis robot picks up the wafers from the loading station and places them very quickly and precisely on the so-called flipper (turning station). Two grippers from the manufacturer Gimatic pick up the wafer. The swivel unit turns the wafer, which arrives on the wrong side, absolutely synchronously. Finally, the grippers place the wafer on the so-called aligner, where it is aligned for further transport. Here, an imaging camera reads the wafer's barcode. The transfer machine then transmits the information contained in the barcode and the exact position of the wafer via Ethernet to the next processing station, which then carries out the correct process in the right place fully automatically.

200 wafers per hour

A precision toothed belt drive ensures that the grippers run absolutely synchronously.

© Gimatic

"This automation saves the user the time-consuming transport process and allows them to focus on their core task, such as laser ablation of layers," says Thomas Rölz, explaining the need to invest in a machine whose complexity only becomes clear on closer inspection. However, the fact that it adds around 200 wafers per hour to the process in a fully automated process approved for cleanroom class 1 justifies the investment.

Specifically, two Gimatic grippers of type MPPM 1606 and a swivel unit of type MRE 25180 are being used in the turning station for the first time. "We wanted to move away from pneumatics because they caused too much abrasion in our previous machines, were too large, too complex to implement and could not handle the wafers gently enough," says Head of Development Wollstadt, explaining the switch from pneumatics to mechatronics. In particular, the abrasion caused by the pneumatics was no longer acceptable, because laser marking in the micrometer range must be absolutely particle-free.

The Hechingen-based company Gimatic was able to implement both of these important features for Innolas with its components - both rotation and a very compact design. The fact that the grippers in question have a gripping force safety device even when de-energized was also a decisive criterion for their use. "The fact that the gripper remains in the state it was last in, even if the machine breaks down, is a very important point," emphasizes Sven Wollstadt. This is particularly important for the undefined states of the swivel unit. It goes without saying that the energy-efficient operation of the components also means that the individual steps of the EU Energy Efficiency Directive to reduce primary energy consumption by 20% by 2020 can be met with the methodology: power on once - end position - done.

"We are pioneers with this pinball machine and the self-sufficient parallel mode of operation," the Innolas Development Manager is convinced. In conventional systems, the robot transports and turns the wafer one after the other.